Cyclic monoenes are useful intermediates for a number of commercial products. For example, cyclododecene is a precursor to the production of polyamides. Cyclododecene can also be converted to cyclododecanoic acid which has been used as a pesticide.
There are several techniques for converting cyclic polyenes to cyclic monoenes, but they are generally not very economically satisfactory, due to low purity of final products, low product yield, or ineffective catalyst preparation. For example, ruthenium carbonyl phosphine complex, besides its high cost, frequently requires long reaction time to reach a product purity of about 95%. In the hydrogenation of polyenes to monoenes catalyzed by cobalt carbonyl phosphine complex which is cheaper than the ruthenium complex, a higher loading of the catalyst is generally required. For example, Bulletin of Chemical Society of Japan, Vol. 40, No. 11, pp. 2718-2719 (1967) discloses that, in order to get a high selectivity to cyclodecene, it requires a high catalyst loading of 9.94 g of cobalt tricarbonyl tributylphosphine per mole of cyclododecatriene.
Additionally, the aforementioned reference discloses preparing the cobalt complex catalyst using benzene or diethyl ether. The cobalt carbonyl phosphine complex is partially soluble in these solvents and so it cannot be effectively separated from the solution mixture, resulting in reducing the recovery of the catalyst and in contaminating the catalyst which, in turn, has lowered catalytic activity. Furthermore, the use of benzene should be discouraged because of its potential carcinogenicity.